varnishing.... lessons learned

I've today sanded all 31 doors ready for their final coat. That's on top of stripping back almost the entire interior of Phoenix and revarnishing.

Along the way, i've learned a fair bit about how to get good results with varnish!.. here's the benefit of my experience...

Preparation, preparation and preparation.... without it, the end results will NEVER be as good as you'd like... want that glass like finish?... prep and more prep... once you've sanded it back to clean good wood, do it again. And then once more. You can never over prepare. (I guess the one exception is when you're varnishing a veneer... don't sand through it!)

I start with varnish remover... I use Nitromors... I tried others, and they either don't work as well, or leave a stick residue. Various people advise scrapers, rather than remover. I find it nearly impossible to avoid damaging the surface with small scratches.... and that just means more sanding. I do however scrape gently to remove the Nitromors. Despite what it says on the tin, I find that you hardly need to leave it any time.. 5mins is plenty, and then a second coat.. another 5 mins and you are ready. A set of scrapers of different shapes and profiles helps... and keep them reasonably sharp... a small file helps here... also round off the corners of flat scrapers... stops you accidentally marking the wood.

Next comes fine wire wool. Be methodical. Follow a pattern to make sure you've not missed anything.... when the dust lays on the surface its easy to do so.

Then brush the dust off... I use a large 4 inch brush kept specially for his purpose.... now its remove the dust time.... don't get carried away at this stage... a quick brush up is enough.

Then 150 grade sandpaper... I use a power sander... the sort designed for detail sanding... a gentle run all over...

another brush up...

Then a final fine sand with a 200 ish grade....

Then brush up... now get the hoover out... open up the boat, get a breeze through... work from the top of the boat down with the 4 inch brush and knock the dust off everywhere.... it will be everywhere!

Brush and hoover again... then brush and hoover again.... this takes a long while... you NEED to remove as much of the dust as you can... the dust ruins the finish.

Finally, wipe the wood down with white spirit. Don't use water as it raises the grain and spoils the lovely flat finish you've created.

After this, final effort is to use a tack rag to remove the very last remnants of dust.

Now for the good bit... the varnishing...

I use Epifanes Tung oil varnish... gives a lovely finish in my opinion.

A really good quality brush with natural bristles... if its new, I brush the wood with it for half an hour first, dry to wear the bristles in... (you did say you wanted the perfect finish didn't you?)

Then the first coat 50% thinned...

let this coat dry thoroughly... it can take several days if its cool, but when its warm, i've found it dry in 24hrs... watch for corners etc, where remains will stay tacky for longer....

Once dry, I give this first coat a VERY light sand with 400 grade paper to just knock any dust nibs off....

and then brush, hoover, air through the boat, tack rag etc etc

Second coat is 25% thinned..... repeat above advice.....

Third and fourth coats are unthinned... sand and then brush etc between

Final coat.... if its to be gloss, then 10% thinned and put it on carefully avoiding a drying edge...

if its matt (again, I use the Epifanes Brush effect matt varnish), then I don't thin...

More coats is good.... for feature woodwork, i've gone up to 6, but i've heard tales of people putting a dozen or more coats on. One thing's for sure, the more coats you use, the glassier the finish.

I finally have discovered that the varnish takes several weeks to go truly hard... so treat it with care for a while.

And, if you can put the effort in, you'll get a glorious finish....

Now, i'm off to varnish 31 doors for the 5th time.